What grade of gas to use?

[dmax2]

Bought a 1980 Starcraft with a 140HP 4 cyl. Should I use a Lead additive or just go with maybe midgrade unleaded gas. Called Mercury and some women told me to use the lead additive. Boat and motor are in like new condition, just don't want to mess the engine up. Thanks for any help you can give me. Dave

 

[mkast]

Re: What grade of gas to use?

You don't need the additive, I'd like to hear why she said to use it.
You can use 87 octane fuel, I'm guessing that's what's in the operators manual.

 

[dmax2]

Re: What grade of gas to use?

I agree with you but the manual I have says to use leaded gas. 2nd owner said he just used mid-grade and he bought from original owner. Still have a few weeks to go before it is in the water. Thanks again, and any more help is welcome. Dave

 

[haulnazz15]

Re: What grade of gas to use?

Well unleaded gasoline has been used since about 1973 and pretty much all engines ran on UL by 1976, so I can't imagine a 1980-built engine would need a lead additive.

 

[HT32BSX115]

Re: What grade of gas to use?

Howdy,


I had a 66 Mark Twain with a 150 Mercruiser. It got unleaded gas for most of the 40 years my dad and I owned it. The engine was worn out when I sold it but it never had the head off and would still pull skiers and run about the same speed it ran when it was new.

You don't need a lead substitute. I would run regular gasoline in it too.


Cheers,


Rick

 

[jkust]

Re: What grade of gas to use?

I have an 84 outboard that requires lead. I used leaded gas when we bought it in 84 and soon after leaded gas went away so used additive since. I looked into this for another post a long time ago but yes a 1980 was made for lead gas if my memory serves me.

 

[df909]

Re: What grade of gas to use?

Unleaded will work just fine.

 

[dmax2]

Re: What grade of gas to use?

Thanks for the help. Unleaded it will be. Dave

 

[bigskiohio]

Re: What grade of gas to use?

i Know people will disagree but i put in the highest test i can get 92, 93, and sunoco 94 .

 

[df909]

Re: What grade of gas to use?

If you're the least bit worried, use an additive like Engine Boost 2.0, or Extreme Fuel Treatment, or something like that. It'll give you extra lubrication, increase the octane, keep the combustion chamber clean, and improve mileage a bit. You can go to www.extrampg.net for more info.

(Please don't take this as a way to plug a product- I've had good success with it and recommend it based on what I use it for)

 

[HT32BSX115]

Re: What grade of gas to use?

i Know people will disagree but i put in the highest test i can get 92, 93, and sunoco 94 .

You can of course, put in what ever you want.

If the engine doesn't detonate on 87 octane fuel, you are wasting your money buying "higher test" gasoline.....Higher octane does not mean higher quality (even though it is and always has been marketed that way)

Higher octane gasoline will only prevent detonation in high compression engines. (which will make more power BECAUSE of the higher compression and advanced timing, NOT the higher octane)

If your engine doesn't require higher octane fuel, higher octane fuel will only drain your wallet faster.


No retail (on-road) gasoline in the US contains tetra-ethyl lead. (except 100LL AVGAS and OFFROAD "racing" type fuel) Sunoco below.....

Actually the bottom line is still this from Mercury.

use an additive like..............

Um, Oh yeah....... Stay away from snake oils too.....they suck even more money out of your wallet!!






Regards,


Rick

 

[trendsetter240]

Re: What grade of gas to use?

You can of course, put in what ever you want.

If the engine doesn't detonate on 87 octane fuel, you are wasting your money buying "higher test" gasoline.....Higher octane does not mean higher quality (even though it is and always has been marketed that way)

Higher octane gasoline will only prevent detonation in high compression engines. (which will make more power BECAUSE of the higher compression and advanced timing, NOT the higher octane)

If your engine doesn't require higher octane fuel, higher octane fuel will only drain your wallet faster.


No retail (on-road) gasoline in the US contains tetra-ethyl lead. (except 100LL AVGAS and OFFROAD "racing" type fuel) Sunoco below.....

Actually the bottom line is still this from Mercury.




Regards,


Rick

I run 94 octane gasoline because it is the only option that is ethanol free. The fuel dock at my marina sells 89 octane 5% ethanol only. I fill up there from time to time but prefer to use the ethanol free 94.

 

[HT32BSX115]

Re: What grade of gas to use?

I run 94 octane gasoline because it is the only option that is ethanol free. The fuel dock at my marina sells 89 octane 5% ethanol only. I fill up there from time to time but prefer to use the ethanol free 94.

Gasoline threads are almost as good as "oil" threads.

The arguments over E10 are lengthy. Do a search here on this board and you'll find no shortage of opinions on the use of gasoline containing ethanol.

EPA regulations in the US authorize up to 10% alcohol use. Most gasolines test at less than 10% depending on the part of the country you're in.

All the engine manufacturers authorize and will warrant their engines using up to 10%. It's all that's available in the US today...

If you have a fiberglass tank in an older boat........ You should not leave E10 in the tank for extended periods of time because E10 can work on some older formulations of the resins used in manufacturing the tank (I would replace the tank with a plastic or aluminum tank)

If you're going out of your way to get racing gas that is specifically devoid of alcohol, I think you may be wasting your time and money if it costs a LOT more than regular pump gas. I have tried it all in every engine I own.

I could never tell any difference..........

Of course, "to each his own"

 

[trendsetter240]

Re: What grade of gas to use?

Gasoline threads are almost as good as "oil" threads.

The arguments over E10 are lengthy. Do a search here on this board and you'll find no shortage of opinions on the use of gasoline containing ethanol.

EPA regulations in the US authorize up to 10% alcohol use. Most gasolines test at less than 10% depending on the part of the country you're in.

All the engine manufacturers authorize and will warrant their engines using up to 10%. It's all that's available in the US today...

If you have a fiberglass tank in an older boat........ You should not leave E10 in the tank for extended periods of time because E10 can work on some older formulations of the resins used in manufacturing the tank (I would replace the tank with a plastic or aluminum tank)

If you're going out of your way to get racing gas that is specifically devoid of alcohol, I think you may be wasting your time and money if it costs a LOT more than regular pump gas. I have tried it all in every engine I own.

I could never tell any difference..........

Of course, "to each his own"

Yeah I know what you mean, I've read my share of oil threads on here. Ethanol too.

I don't really go out of my way except that I have to fill portable tanks at the gas station and bring them down to my boat. The 94 octane is sold at all the Chevron stations here in vancouver, one is on the way from my house to my dock.

Here it's labled at the pump, shell has 91 octane that is ethanol free, chevron's only ethanol free is 94 octane. Price at the gas station for 94 is comparable to the price at the marine dock for 89. Of course I could save money by getting 87 at the gas station.

Either way, I don't burn enough gas for the cost difference to affect my boat use. I have certainly sneaked a few 5 gallon jugs of 87 in when I have been short on funds

I had an ethanol problem with a motor in the past; ran great on the dino gas then after one tank of E10 needed a carb overhaul. Bits of rubber came loose from somewhere in the fuel system and blocked the inlet in to the carb bowl on top carb. Been ethanol free whenever possible since.

 

[Black as]

Re: What grade of gas to use?

Just purchase what ever the manufacturer recommends and be done with it and then go out and have some fun

If you cant afford the fuel you shouldn't buy a boat

 

[HT32BSX115]

Re: What grade of gas to use?

Well, if you can buy it by going to a "regular" gas station, that's a good reason to use it.

The (%) difference in (grade) price now is not what it was years ago when gas was much cheaper.

So if you could get non-ethanol gas that might be good reason to use it. Especially if you're storing the boat for the winter etc.

I would test it though. I don't trust retailers. They have been known to label gas pumps incorrectly.

Here's a good youtube video on how to test for E10

http://www.youtube.com/watch?v=gsSQSuCiUjE

 

[trendsetter240]

Re: What grade of gas to use?

haha..you know what, I think I will test it when I get a chance! Thanks for the youtube link.

Is the ethanol content mandated in the states? Here in Canada it is typical to see 87 octane 10% ethanol, 89-5%, 91 or 94 is ethanol free. Some companies are the opposite and actually market the fact that they have ethanol..e.g. "mother nature's gas station" and all their gas is 10% ethanol.

I couldn't care less for my car, it's a high comp engine and requires 91+ octane but I have run E10 many times without any difference.

 

[cr2k]

Re: What grade of gas to use?

Well the problem with using additives in lieu of higher grade gas is the additives add anywhere from $0.50 to over $1.00 per gallon in cost. It only $0.10 to $0.30 per gallon to up in fuel grade.

How this would apply to boating is anyones guess; My PU is set for regular 87 oct. I put 89 in it and get better performance PLUS about 2mpg more out of my fuel. Do the math, for $0.10/gal more it is cheaper to run 89 for me.

If one wants to run regular, just back the timing off a few degrees to cover it if it knocks.

We usually set timing back a few degrees on the older stuff. In CA the highest grade is 90. 87-89-90 We got screwed. But the additive mfg. like it.

So basically, run whatever grade you want and adjust the timing if needed.